Pneumatic rock drill



April 13, 1937. A c. A. .HULTQUIST 2,076,644

' PNEUMATIC RQCKYDRILL original Filed oct. 22, 193.4 s sheetssheet 1 v 3Shee'ts-Shet 2 o 8. l? l INVENTOR. Char/e5 A. Ha/qa/Ls BY Q MIM/wdATTORNEY c. A. HULTQUIST PEUMATIC ROCK DRILL originalFiled oct. 22,19:54

April 13; 1937.

April 13,V 1937. c. A. HULTQuls-r PNEUMATIC ROCK DRILL Original FildOct. 22, 1934 A3 Sheets-Sheet 3 n0. mdf I m# n w F M m w A@ n. md. Cv.B, A ow 5 3, y E R f? R j .17 K 4| /V/f/ z a, 3 a

Patented Apr. 13, 1937 FFICE PNEUMATIC RO CK DRILL Application October22, 1934, Serial No. '749,411 Renewed May 26, 1936 9 Claims.

My invention relates to pneumatic rock drills, more particularly tomechanism used in combination with rock drills for blowing the drillcuttings and the like from the drill holes when drilling in rock orother material.

It has heretofore been the custom in pneumatic rock drills of this classwhen blowing the drill cuttings from the drill holes to waste a largeproportion of the air by passing it out through the leak holes of thedrill, thus wasting a large quantity of air and at the same timereducing the emciency or quantity of air delivered to the drill holethrough the drill.

The objects of my invention are:

First, to provide a pneumatic drill in which there are no open holes orother leak places through which the compressed fluid is wasted when usedfor blowing the drill cuttings out of the drill holes;

Second, to provide a pneumatic rock drill of this class in which thehammer is stationary during the blowing operation and the full receiverpressure is delivered into the drill hole in the drill steel for blowingthe cuttings from the drill 25 hole, therefore providing a highlyefficient and effective means of clearing the drill hole of cuttings orthe like;

Third, to provide a pneumatic rock drill of this class that is veryeconomical in its use of the com- 30 pressed air while at the same timeproviding a maximum drilling speed that is economical of maintenance andeasy and convenient to operate;

Fourth, to provide a pneumatic rock drill of this class with plungervalve means cooperative 35 with the conventional rock drill structure.for adding eiciency to the blowing of cuttings from the drill hole andeconomy of air used in this operation; and

Fifth, to provide a pneumatic rock drill of this 40 class which is verysimple and economical of construction, easy to operate, eilicient in itsaction throughout all of its operations, and which will not readilydeteriorate or get out of order.

With these and other objects in view as will 45 appear hereinafter, myinvention consists of certain novel features of construction,combination and arrangement of parts and portions as will be hereinafterdescribed in detail and particularly set forth in the appended claims,reference 50 being had to the. accompanying drawings and to thecharacters of reference thereon which form a part of this application,in which:

Figure l is a longitudinal sectional view of my pneumatic rock drillcomplete through I-I of 55 Fig. 2 showing some of the parts in elevationto facilitate the illustration and showing by dotted lines varyingpositions of the throttle operating handle, and showing the drill inblowing position with the piston 22 held stationary on the end of thefront bearing 'I4 and the hammer end 24 resting on the face of the steelshank 2l; Fig. 2 is a back end View thereof; Fig. 3 is a fragmentarysectional view substantially along the line 3-3 of Fig. 1 on an enlargedscale showing some of the parts in elevation to facilitate theillustration, and showing the hammer piston 22 on its return stroke indrill operating position; Fig. 4 is a longitudinal sectional view onapproximately the same scale as that of Fig. 1 of my pneumatic rockdrill complete along the line 4-4 of Fig. 2 and showing some of theparts and portions in elevation to facilitate the illustration, andshowing the drill in drilling position with the hammer piston 22 on itsdownward or working stroke; Fig. 5 is a transverse sectional viewthrough the back head along the line 5-5 of Fig. 4, and Fig. 6 is afragmentary longitudinal sectional View through 6 6 of Fig. 4 showingsome of the parts and portions in elevation to facilitate theillustration.

Similar characters of reference refer to similar parts and portionsthroughoutthe several views of the drawings.

As in the conventional rock drill of this classl my rock drill isprovided with a back head 5 at the back end of the rock drill and it isprovided in one side with a throttle bearing 6 in which there isrevolubly mounted a throttle valve member. I which is provided with anextended portion la and on which is mounted an operating handle 8 whichhandle is shown in its operating position in Figs. 2 and 3 of thedrawings, and in its inoperative position and its drill hole blowingposition by dotted lines in Fig. 1 of the drawings.y Screwed into theopposite end of the throttle bearing 6 from the handle 8 is an air inletspud S, shown best in Figs. 3 and 6 of the drawings, into which may bescrewed the air hose or other air conductor from the air compressor ortank.

The back head 5 is also provided on the opposite side from the throttle'I with a hole I0 which is adapted for a handle for supporting the drillduring the drilling operation. Mounted centrally in this back head 5 andextending forwardly to near the opposite end of the drill is a watertube II which is held in a fixed position in the back head 5 by the backplug I2 and rubber washer I3, shown best in Figs. 1 and 4 of thedrawings. This back head 5 is also provided with a water Chiot I4 forconducting water into a groove I5 in sol 'I'his rifle bar 29 is providedwith a plurality of helical flutes 20w which engage conformingy helicalridges cut in the rifle nut 2| whichrie nut is screwed into the piston22 at its back end and surrounding said rifle bar 20. This constructionprovides the hammer piston 22 with a rotating movement when it travelsback and forth in the cylinder I8 and this rotating .move-v ment of thehammer Ypiston 22 is conveyed to the chuck driver 23 by means of utescut on the hammer extension 24 and which engage notches 25 in the chuckdriver 23. This inturn rotates the drill steel 26 which is supported inthe chuck driver 23 by a hexagon shank 21.

Mounted in the enlarged counter bore I1 in the cylinder I8 is a valveVchest 28 in which reciprocatesl a tubular distributing or control valve29. This control valve 29`rides on a bearing 30 which is also .tubularand fits loosely on the riiie bar 29. At the front portion of mypneumatic rock drill there is provided a front head 3|; VThe back headV5 and this front head 3| and the intermediate parts vare 'held in'rigidalinement by 'two side bolts 32 which pass through perforated lugs inthe back head'5 and the front head 3|, which bolts are shown only inFig.2 of the drawings as'they are conventional supporting bolts.

It will also be notedthat the structure so far described in detail'issubstantially of conventional form of pneumatic rockdrills of this classbut is necessary for cooperative relation with the novel portionV ofmypneumatic rock drill structure described'hereinafter.

Applicant has provided in the back head 5 and rearfcylinder'l plungeryvalves 33 and 34,

shown'best in Fig. 6 of the drawings, which are adapted to close theleak hole 35 and valve operating port 36 in the rear cylinder I8, asshown best in Fig. 6 rof the drawings, for saving the compressed' fluidduring the blowing of drill cuttings from the Vdrill hole. These plungervalves 33 and 34 consist of plunger members 1I and 12 which. are adaptedto fill and reciprocate in the ports 36 and 59,`respectively, and eachof the plunger valves is provided with a spring, designated 31 and 38,respectively, which are mounted inl bores in the back head 5 and rest onshoulder'siinsaid back head, as shown best in Figs. 3 and 6 ofthedrawings. The plungers Hand 12 are also provided with pistons 69 and 10which are mounted in enlarged bores in the back head 5, as shown best inFigs.'3.and 6 of the drawings. Backwardly of the pistons 69 and' 10 arevprovided reduced air receiving bores 61 and 68 which are adapted toreceive air through ports 64 and 65 in the back head5 through openings62 and 63 in the throttle 1 which receive their air through port 49, allas shown best in Figs. 1 and 3 of the drawings.

The operation of my drill Vfor the ordinary drilling purposes is asfollows: It will be noted that Figs. 3 and 4 show the drill for drillingpurposes. I'he plunger valves 33 and 34 are held in their rearwardposition by springs 31 and 38. Fluid' under pressure enters throughthreaded openings 39 in thek air inlet Spud S into the hollow -port5I).V

open portion 40 of the throttle valve 1. Then it passes through the mainsupply port 4I to the back head port 42 and into 'the chamber 43. Thenthrough the ports 44 into the central groove 45 in the valve chest 28and then the fluid is distributed by the distributing valve 29. In Fig.4 the valve 29 is inits rearward position and the fluid passes from thegroove 45 into the groove 46 and the port 41 into the rear end 48 of thecylinder bore which drives the piston 22 forwardly onrits workingstroke. At the same time the front end 49 of the cylinder bore isexhausting through the cylinder ports 50,*groove 5|, and

exhaust ports 52.

It will be here noted that the valve 29 is held in its position by the.greater pressure against the central ridge 53 and this ridge is largerin flowing into the front cylinder bore 49 from the central groove 45,through the groove 5| Vand Afterfthe hammer extension 24 has deliveredVthe blow on the end of the steel shank 21 the pistonA 22 will start onrits return stroke and continue rearwardly until valve operatingv port 59is uncovered. Fluid will then ow through rearward position and `causesthe piston 22 to again travel forwardly.

These actions of the different parts will con- Y tinue as Vlong as thedrill is'in its drilling position and the uid under pressure flows intothe groove 45. i

The operation for blowing cuttings from the drill hole is as follows:Fig. 1 shows the position of'the hammer and other operating parts forthis operation. The operating handle 8 is turned to a position at rightangles to the longitudinal axis of the drill, as shown by one positionin Fig. 1 of the drawings which is the horizontal position on thedrawings. In this position the ducts 62 and 63 in the throttle valve 1coincide with the ducts 64 and V65 and the iiuid supply port 66 iiowsthrough the port 59 into the groove 60 and holds the valve 29 in itsrearward position. At

the same time the plunger 1| has closed the valve operating port 36 fromcommunicating with the groove 56` but the leak port 13 remains open tothe atmosphere'as best shown in Fig. 4. It will thus be seen that nofluid under pressure can be wasted through the leak holes 35 and13;thatV the valve 29 is held securely in its rearward position; thatthe hammer piston 22 is restingfagainst the front bearing 14. Thisequalizes the upward and downward pressure in the cylinder andeliminates al1 tendency to push the drill upward during blowingoperations. The rifle nut 2| has Cil grooves 'l5 through which thecompressed fluid flows into'the hollow portion 16 of the hammer piston22, thence along the tube I I until the uid enters the hollow steel 26for blowing the drill cuttings from the drill hole.

It will behere noted that the leakage between the faces of the hammerand steel at 11 is very small. It will therefore be seen that this is avery efficient way of blowing the cuttings from the hole. After theblowing is completed the throttle handle 8 is turned until it is in aposition parallel with the longitudinal axis of the drill or drillingposition; the fluid pressing on the pistons 69 and 1U is exhaustedthrough the grooves 13 and 19 and Vent holes 80 and 8|. Then the springs31 and 38 return the plunger valves 33 and 34 to their rearward positionand the drilling operation is resumed.

Though I have shown and described a particular construction, combinationand arrangement of parts and portions, I do not wish to be limited tothis particular construction, combination and arrangement but desire toinclude in the scope of my invention, the construction, combination andarrangement substantially asset forth in the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and distributing valve in saidback cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controllediluid pressure operated leak hole valves in said back head in operativerelation with said leak holes and said throttle for closing the sameduring the blowing operation of said rock drill.

2. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and distributing valve in saidback cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak hole valves in said back head in operativerelation with said leak holes and said throttle for closing the sameduring the blowing operation of said rock drill, and means in saidthrottle for regulating said leak hole valves.

3. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and distributing valve in saidback e cylinder, the combination with said back head,

throttle, back cylinder with leak holes and distributing Valve, ofthrottle controlled fluid pressure operated leak hole valves in saidback head in operative relation with said leak holes and said throttlefor closing the same during the blowing operation of said rock drill,said leak hole valves including compressed air cylinders, pistonsmounted therein, plunger members secured to said pistons reciprocallymounted in ports communicating with said leak holes, and springs mountedaround said plungers in engagement with said pistons tending to returnsaid pistons to backward position.

4. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and distributing valve in saidback cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak hole valves in said back head in operativerelationfwithsaid leak -holes and said throttle for closing the sameduring lthe blowing operation of said rock drill, and means'in saidthrottle for regulating said leak hole valves, said means in saidthrottle including ports communicating with the interior of saidthrottle and positioned to communicate with said leak hole valves whensaid throttle is turned to a certain position.

5. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and distributing valve in saidback cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak hole valves in said back head in operativerelation with said leak holes and said throttle for closing the sameduring the blowing operation of said rock drill, said leak hole valvesincluding compressed air cylinders, pistons mounted therein plungermembers secured to said pistons reciprocally mounted in portscommunicating with said leak holes, springs mounted around said plungersin engagement with said pistons tending to return said pistons tobackward position, and means in said throttle for regulating said leakhole valves, said means in said throttle including ports communicatingwith the interior of said throttle and positioned to communicate withsaid leak hole Valves when said throttle is turned to a certainposition.

6. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and a distributing valve insaid back cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak valve means in said back head in operativerelation with said leak holes and said throttle for closing said leakholes when said throttle is turned to a certain position.

7. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and a distributing valve insaid back cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak valve means in said back head in operativerelation with said leak holes and said throttle for closing said leakholes when i said throttle is turned to a certain position, and meansfor returning said valve means to inoperative position relative to saidleak holes when said throttle valve is turned to a different position.

8. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and a distributing valve insaid back cylinder, the combination with said back head, throttle, backcylinder with leak holes and distributing valve, of throttle controlledfluid pressure operated leak valve means in said back head in operativerelation with said leak holes and said throttle for closing said leakholes when said throttle is turned to a certain position, and means forreturning said valve means to inoperative position relative to said leakholes when said throttle valve is turned to a different position, thesame throttle adapted to control said leak hole valves and control thedistributing valve.

9. In a pneumatic rock drill in which there is a back head a throttletherein, a back cylinder with leak holes and a distributing valve insaid back cylinder, the combination with said back Gil head, throttle,backcylinder with leak-holes and distributing valve, of throttlecontrolled iiuid pressure operated leak valve means inV said back headin operative relation with said leak holes and said throttle for closingsaid leak holes when said throttle is turned to a certain position, andmeans for returning said valve means to inoperative position relative tosaid leak holes ,when

said throttle valve is turned to a different position, the samethrottle; yadapted to control said leak hole valves and( control thedistributing valve, said leak hole valves being so arranged in theoperating ports of' said rock drills'to control the position of saiddistributing valve and the hammer of said drill, while said leak rholevalvesr are in operative position in relation to said leak holes.

, CHARLES A. HULTQUIST.VA

